Improvement in balanced slide-valves for steam-engines



J. F. WALLACE.

Balanced S|ide-Vavlves for Steam-Engines. N0. 143,043, Pate'nredSeptember23.1873.,

.- IIII 7 JNITED STATES PATENT OEEIcEC JOHN F; WALLACE, OF PITTSBURG,PENNSYLVANIA.

IMPROVEMENT IN BALANCE!) SLIDE-VALVES FOR STEAM-ENGINES.

Specification forming part of Letters Patent No. 143,043,6ated September23,1873; application filed .June 12, 1873.

To all whom t may concern Be it known that I, JOHN F. WALLACE, of thecity of Pittsburg, in the county of Allegheny and State of Pennsylvania,have invented a certain new and useful Improvement in Slide-Valves; andI do hereby declare that the following is a full, clear, and exactdescription thereof, reference being had to the accompanying drawing andto the letters of reference marked thereon.

My invention consists in lengthening the slide-valve, and'enlarging theupper end of the receiving-ports of the cylinder, and reducing thebearings ofthe valve-seat so that they will wear equally, and therebyprevent the valve from becoming rounded on its face. My invention alsoconsists in the use of a iiexible packing-platein combination with asuspended plate for relieving the upper surface of the valve from unduepressure of the steam.

To enable others skilled in the art to make and use my invention, I willproceed to describe more fully its construction and operation.

In the accompanying drawing, which forms part of my specification,Arepresents the steamcylinder. B represents the receiving or steamports, and C represents the exhaust-port. Th e upper ends ofthe receiving-ports B are enlarged for the purpose of reducing the bearings of thevalve D, and it is lengthened so that its bearings will cover the outerbearings of its seat and the steam-ports B. By this construction ofthevalve, its seat, and the enlarging of the upper end of the steam-ports,the wear of the valve and of its seat will be uniform, thus preventingthe rounding of the face of the valve, which is a difculty common toslide-valves of locomotive-engines, and also of other engines, in whichthe slide-valve has a rapid motion. The valve D is provided with anupper face, e, which is secured to the top of the valve D through themedium of boltsf. Above this upper face is suspended, to the lid 7a ofthe steam-chest 7c, through the medium of two or more bolts, a plate, g,which is sometimes called balancing-plate. The bolts j are provided withscrew-threads and pass through a jam-nut, l, provided with correspondingscrewthreads. rlhe outer walls of the jam-nuts are also provided withscrew-threads which con form to screw-threads of the lid 71, into whichit is screwed. The bolts j are prevented from turning by means of theplate m, which has in each end arecess which islitted to the upper endsof the bolts j. The recessed ends of the plate m rest upon the jam-nutl. Above the balancing-plate g is placed a thin plate, n, ofsheetcopper, to the outer edge of which is secured a metal ring, o,whichis used as a packing for the balancing-plate g.- The copper plate n isprovided with openings for the bolts j, and the lower ends of thejam-nuts l hold the plate a down upon the balancing-plate g and pack thejoints around the bolts j. The set-screws P, in combination with thespiral springs s, are used for the purpose of preventingthe packin g-rings from jarring or vibrating on the upper face of the valve D. One ofthe bolts, j, is provided with an opening, w, through it, and in theupper end is placed a stop-cock, t, and to this may be attached a pipeleading into the stack of the locomotive. The object of this stop-cockand opening through the bolt is to carry oli' steam in case there shouldbe a leakage of it under the balancing-plate g. y representsthevalve-yoke, which is constructed in the ordinary manner. Thebalancing-plate can be adjusted With relation to the top surface of thevalve through the medium of the bolts j and jam-nuts l, the operation ofwhich will be readily understood by the skillful mechanic.

The advantages of my improvement in slidcvalves are briey stated, asfollows: First, the tendency of the valve to Wear rounding on its face,and thereby leak steam, is avoidedby lengthening the valve anddiminishing its seat by enlarging the upper ends of the steam-ports.Second, the upper surface of the valve is relieved from undue pressureof steam through the medium of the balancing-plate, exible plate ofcopper, and packing-ring. Third, the balancing-plate is perfectly packedthrough the medium of the packing-ring, thereby increasing theefficiency of the balancing-plate. Fourth, the tendency of thepacking-ring to vi brate is obviated by means of the setscrews andspiral springs used in combination with them. Fifth, the valve isrelieved from friction by increasing its length and' diminishing itsseat. Sixth, the valve is nearly balanced by means of v thebalancing-plate, thereby enabling thc engineer to handle it with easeand facility, which is a great consideration in slide! valves oflocomotive engines. Seventh, the balancing-plate can be adjusted Without'removing the lid of -the steam-chest, and such adjustment can beaccomplished with ease and facility. Eighth,in case the balancing deviceshould become impaired, so as to leak steam, the steam under thebalancing-plate can be carried olf through the hollow bolt and stopcoekinto the locomotive-stack. Ninth, in the event of the balancing-plateand packin g-rin g becoming inoperative, the valve can be used as theordinary slide-valve without stopping the engine to make repairs, whichis a great advantage when the locomotive and its train are under Way onthe road. i

Having thus described my improvement, what I claim asl of my inventionis- 1. The combination of the lengthened valve D with the valve-seat,having the steam-ports enlarged in it their entire Width, substantiallyas herein described, and for the purpose set forth.

2. The combination of the balancing-plate g, packing-ring o, exibleplate n, bolts j, and jam-nuts Z with the slide-valve D, substantiallyas herein described, and for the purpose Set forth.

3. The combination of the set-screws P and springs s with thepacking-ring o and flexible plate a, substantially as herein described,and for the purpose set forth.

4. The bolt j, provided with an opening, w, through it, in combinationwith the stop-cock t, balancing-plate g, and packing-ring o,substantially as herein described, and for the purpose set forth.

JOHN F. WALLACE.

Vitnesses:

A. C. J OHNsTON, JAMES J. JOHNSTON.

